LM2619  Product Folder

The LM2619 step down DC-DC converter is optimized for powering circuits from a single Lithium-Ion cell. It steps down an input voltage of 2.8V to 5.5V to an output of 1.5V to 3.6V at up to 500mA. Output voltage is set using resistor feedback dividers.

The device offers three modes for mobile phones and similar portable applications. Fixed-frequency PWM mode minimizes RF interference. A SYNC input allows synchronizing the switching frequency in a range of 500kHz to 1MHz. Low current hysteretic PFM mode reduces quiescent current to 160µA (typ.). Shutdown mode turns the device off and reduces battery consumption to 0.02µA (typ.).

Current limit and thermal shutdown features protect the device and system during fault conditions.

The LM2619 is available in a 10 bump micro SMD package. This packaging uses National's chip-scale micro SMD technology and offers the smallest possible size. A high switching frequency (600kHz) allows use of tiny surface-mount components.

The device features external compensation to tailor the response to a wide range of operating conditions.

• Sub-miniature 10-bump thin micro SMD package
• Uses small ceramic capacitors
• 5mV typ PWM mode output voltage ripple(C_OUT = 22µF)
• Internal soft start
• Current overload protection
• Thermal Shutdown
• External compensation

• Operates from a single LiION cell (2.8V to 5.5V)
• Output voltage (1.5V to 3.6V)
• ±1% DC feedback voltage precision
• 500mA maximum load capability
• 600µA typ PWM mode quiescent current
• 0.02µA typ shutdown current
• 600kHz PWM switching frequency
• SYNC input for PWM mode frequency synchronization from 500kHz to 1MHz
• High efficiency (96% typ at 3.9V_IN, 3.6V_OUT and 200mA) in PWM mode from internal synchronous rectification
• 100% Maximum Duty Cycle for Lowest Dropout

• Mobile Phones
• Hand-Held Radios
• RF PC Cards
• Wireless LAN Cards